1. Field of the Invention
The present invention relates to an electron beam exposure apparatus and an electron beam deflection apparatus.
2. Description of the Related Art
FIG. 1 is a diagram showing a configuration of an electron beam deflection apparatus 400 according to a conventional electron beam exposure apparatus. The electron beam deflection apparatus 400 includes a substrate 500, apertures 600, 610, and 620 provided in the substrate 500, and deflectors 510, 520, and 530 provided at the apertures 600, 610 and 620 respectively. In the electron beam deflection apparatus 400, the electron beams which pass through the apertures 600, 610, and 620 are independently deflected by applying voltage to deflecting electrodes of the deflectors 510, 520, and 530.
However, in the electron beam deflection apparatus 400 including the plurality of deflectors 510, 520, and 530, there is a problem that an electric field generated by a predetermined deflector affects electron beam other than the electron beam which passes through a predetermined deflector. For example, negative voltage is applied to the deflecting electrode of the deflector 510 so that the electron beam which passes through the aperture 600 is to be deflected, while positive voltage is applied to the deflecting electrode of the deflector 530 so that the electron beam which passes through the aperture 620 is to be deflected. Moreover, voltage is not applied to the deflecting electrode of the deflector 520 in order to let the electron beam, which passes through the aperture 610, go straight. However, as shown in FIG. 1, an electric field is generated on the orbit of the electron beam which passes through the deflector 520 due to an electric potential difference between the deflector 510 and the deflector 530, and the electron beam which passes through the deflector 520 is deflected in a direction of the deflector 530 to which the positive electric potential is applied.
Accordingly, it is an object of the present invention to provide an electron beam exposure apparatus and an electron beam deflection apparatus which can solve the foregoing problem. The object can be achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention.
In order to solve the foregoing problem, according to the first aspect of the present invention, there is provided an electron beam exposure apparatus for exposing a pattern on a wafer by a plurality of electron beams. The electron beam exposure apparatus includes: an electron beam generating section for generating the plurality of electron beams; a deflecting section including a plurality of deflectors for deflecting the plurality of electron beams respectively; and a screening section including a first screen electrode provided between the plurality of deflectors along an irradiation direction of the electron beam, wherein a distance between an upper end of the first screen electrode and the electron beam generating section is shorter than a distance between a distal end of the deflectors and the electron beam generating section, and a distance between a lower end of the first screen electrode and the wafer is shorter than a distance between the distal end of the deflectors and the wafer.
The first screen electrode may have a gridiron shape, where each of the plurality of deflectors are provided between bars of the grid. The first screen electrode may be provided at circumference of each of the plurality of deflectors.
The deflecting section may be provided in a direction substantially perpendicular to the irradiation direction of the electron beams, and may further include a deflector substrate at which the plurality of deflectors are provided, and the first screen electrode may be attached on the deflector substrate.
The first screen electrode may be provided so that a distance between an upper end of the first screen electrode and the electron beam generating section is shorter than a distance between a distal end of the deflector and the electron beam generating section, and a distance between a lower end of the first screen electrode and the wafer 44 is shorter than a distance between the distal end of the deflectors and the wafer.
The deflecting section may be provided in a direction substantially perpendicular to the irradiation direction of the electron beam, and may further include a deflector substrate at which the plurality of deflectors are provided, and the screening section may be provided substantially parallel with the deflector substrate, and may further include a first screening substrate on which the first screen electrode is attached.
The screening section may include: a second screen electrode provided across the deflector substrate from the first screen electrode along the irradiation direction of the electron beams; and a second screening substrate provided across the deflector substrate from the first screening substrate in a direction substantially parallel with the deflector substrate. The second screen electrode may be attached on the second screening substrate.
The first screen electrode may include a plurality of apertures in a direction substantially perpendicular to the irradiation direction of the electron beams. The first screen electrode may be a grid electrode.
The electron beam exposure apparatus may further include an electron lens section for focusing the plurality of electron beams independently. The electron lens section may include: a first magnetic conductor with a plurality of first apertures through which the plurality of electron beams pass; and a second magnetic conductor with a plurality of second apertures through which each of the plurality of electron beams, which has passed through each of the first apertures, passes, where the second magnetic conductor is provided substantially parallel with the first magnetic conductor. The deflector may be provided inside the first aperture, and the first screen electrode may be provided between the first magnetic conductor and the second magnetic conductor.
The electron beam exposure apparatus may further include an electron lens section for focusing the plurality of electron beams independently. The electron lens section may include: a first magnetic conductor with a plurality of first apertures through which the plurality of electron beams pass; and a second magnetic conductor with a plurality of second apertures through which each of the plurality of electron beams, which has passed through each of the first apertures, passes, where the second magnetic conductor is provided substantially parallel with the first magnetic conductor. The deflector may be provided inside the first aperture. The first screen electrode may provided between the plurality of second apertures of the second magnetic conductor extending from the second magnetic conductor to a direction of the wafer. The screening section may further include: a second screen electrode provided between the plurality of first apertures of the first magnetic conductor extending from the first magnetic conductor to a direction of the electron beam generating section; and a third screen electrode provided between the plurality of first apertures and between the first magnetic conductor and the second magnetic conductor, extending along the irradiation direction of the electron beams.
The screening section may include: a first screening substrate, which is provided substantially parallel with the second magnetic conductor, on which the first screen electrode is attached; and a second screening substrate, which is provided substantially parallel with the first magnetic conductor, on which the second screen electrode is attached.
According to the second aspect of the present invention, there is provided an electron beam deflection apparatus for independently deflecting a plurality of electron beams. The electron beam deflection apparatus includes: a substrate in which a plurality of apertures are provided; a plurality of deflectors provided in each of the plurality of apertures of the substrate; and a first screen electrode provided between the plurality of apertures of the substrate.
The deflector may be provided on the substrate and extending along a first direction which is a direction substantially perpendicular to the substrate, and the first screen electrode may be provided on the substrate and extending along the first direction, wherein the first screen electrode is longer than the deflector.
The electron beam deflection apparatus may further include a second screen electrode provided across the substrate from the first screen electrode along the first direction.
This summary of invention does not necessarily describe all necessary features so that the invention may also be a sub-combination of these described features.